The scanning probe microscopy (SPM) is used to measure a carrier concentration distribution of a semiconductor device. Since the measured result is changed according to a contact state of a probe provided at a tip end of a cantilever with an object to be measured, regarding the SPM; it is necessary to strongly press the probe against the object to be measured. Therefore, the probe is abraded, and abrasion powders are generated. When the abrasion powders enter between the probe and the object to be measured, a contact resistance increases.
As a method for reducing the abrasion powder in a case where physical property information is measured at a plurality of places of the object to be measured, there is a method in which after the measurement has been performed by pressing the probe against the object to be measured at a measuring point, the probe is held above the object to be measured and moved to the next measuring point, and the cantilever is pressed against the object to be measured again.
However, when the probe is completely separated from the object to be measured at every measurement, the measured results are largely varied by a position shift caused at the time when the cantilever is positioned at the next measuring point. Also, there is a problem in that it takes time to position the probe and thus a measurement throughput is lowered.